Legalism is a political philosophy that does not address higher questions pertaining to the nature and purpose of existence. It is concerned with the most effective way of governing society. The legalist tradition derives from the principle that the best way to control human behaviour is through written law rather than through ritual, custom or ethics. The two principal sources of Legalist doctrine were the Book of Lord Shang and the Han Fei-tzu. The Book of Lord Shang teaches that laws are designed to maintain the stability of the state from the people, who are innately selfish and ignorant. There is no such thing as objective goodness or virtue; it is obedience that is of paramount importance.